1. Technical Field
The present invention relates to an ejection rate measurement method, an ejection rate adjustment method, a liquid ejection method, a method of manufacturing a color filter, a method of manufacturing a liquid crystal device, and a method of manufacturing an electro-optic device, and in particular to a method of measuring an ejection rate of a droplet ejected from a liquid ejection head with high accuracy.
2. Related Art
In the past, as a method of ejecting a droplet to a work there is known a method of ejecting it using an inkjet type droplet ejection device. The droplet ejection device is provided with a table for mounting a work such as a substrate and moving the work in one direction and a carriage moving above the table along a guide rail disposed in a direction perpendicular to the moving direction of the table. The carriage has an inkjet (herein after referred to as droplet ejection head) mounted thereon to eject droplets to the work, thus performing coating.
As a functional liquid, which is formed as droplets and then ejected to the work to be applied thereon, there are used various materials. Most of the functional liquids vary in viscosity with temperature, and the fluid resistance varies in conjunction with the variation in viscosity. The variation in fluid resistance causes a variation in the flow rate of the functional liquid flowing through a channel inside the droplet ejection head. The variation in flow rate of the functional liquid causes a variation in amount of ejection per dot, which makes it difficult to measure the ejection rate with high accuracy.
In order for solving the problem described above, a method of measuring the amount of ejection per dot with high accuracy is disclosed in JP-A-2004-209429. According to this method, the droplet ejection device is mounted inside a chamber, and then the temperature and the moisture inside the chamber are controlled, thus the ejection rate is measured while controlling the environmental conditions of the droplet ejection device.
When pressurizing a cavity of the droplet ejection head using a piezoelectric element, apart of the energy applied for operating the piezoelectric element is converted into heat, which causes the temperature of the droplet ejection head to rise. Further, when the piezoelectric element is not driven, the piezoelectric element does not generate heat while the droplet ejection head radiates heat, which causes a variation in the temperature of the droplet ejection head.
Since the ejection rate is influenced by the temperature, a problem of deterioration of measurement accuracy of the ejection rate arises unless the ejection rate is measured in substantially the same head temperature condition at every measurement.